When I was a bit more active in the Star Wars fan circles, something you couldn't escape from was fan fiction. Forums such as TheForce.net and Fanfiction.net each had vibrant communities in the early '00s, and there was a whole range of really interesting stories to really crappy ones. I wrote a couple of the crappy ones - spinoffs from the Rogue Squadron series - and I had a bunch of friends who did as well.
Fan Fiction has interested me for a while now, because it's this really unique way that fandom contributes to genre literature. Stories become more than just an author telling the reader a story: the readers jump in and continue that story.
Go read Unauthorized Stories: Fan fiction and fandom over on Kirkus Reviews.